TRANSACTIONS OF THE SECTIONS. 177 



wool, as the work is done better than by a MacCarthy gin, and nearly as quickly 

 as by a Saw gin, .and it is thus particularly valuable in reference to the short stapled 

 cotton of India, and the long stapled cotton of Egypt. 



On the Effect of Blowing Blast Furnaces with Blast of very High Tempera- 

 tures. By E. A. Cowper. 



Very satisfactory results were obtained in 1860-1861 from a pair of Cowper's 

 hot-blast stoves, heating the blast to a particularly high temperature for one tuyere 

 only for a blast furnace (the other four being blown with ordinary hot blast). These 

 stoves were for a length of time in successful operation at Messrs. Cochrane and 

 Co.'s works at Ormesby, near Middlesborough-on-f ees ; these gentlemen then erected 

 large stoves to supply blast of very high temperature for a whole furnace, which 

 stoves have now been in full operation for upwards of four years with the follow- 

 ing satisfactory results, viz. an increased " make " of iron from the same plant of 

 fully 20 per cent., the iron being of rather improved quality, owing to less impurity 

 being carried in with the fuel, the avoidance of all leakage caused, by the ordinary 

 cast-iron pipes, reduced friction or loss of pressure in the blast passing through 

 the stoves, and a saving of upwards of five hundredweight of coke per ton of iron 

 made, the blast being at 1150° Fahr. These stoves are the invention of Mr. E. A. 

 Cowper, who has adopted the regenerative principle invented by Mr. Siemens, as 

 the means of absorbing the heat rroin the products of combustion and giving it out 

 again to the air to be heated, the regenerators being each enclosed in an iron 

 casing lined with firebrick, and provided with valves to allow of the passage of 

 ignited gas through the stove to heat it, and valves to allow the entrance of the 

 cold blast and exit of the hot blast. The stoves are heated by the combustion of gas 

 obtained from gas producers, such as are now used largely for Mr. Siemens's glass 

 furnaces ; but recent experiments have been made, with the view of separating the 

 gas from the top of the blast-furnace, from the dust it commonly contains, so that 

 such gas may be conveniently used, and it has been found that it is only necessary 

 to cause the gas to travel for some distance at a speed of less than 1 foot per second. 

 in thin layers, in order thoroughly to deposit all the dust contained in it ; and by 

 arranging a number of thin shelves at a small distance apart, and at an incline in 

 a large pipe or box, the dust deposits on the shelves, and can be easily washed out 

 occasionally with great facility by a stream of water, blast, or steam. 



On Siemens's Regenerative Gas-Furnaces and Producers. By S. N. F. Cox. 



The author commenced by stating that the system of regenerative gas-fumaces 

 having now been before the manufacturing world for several years, and having 

 been employed for the manufacture of glass of all kinds, iron, and steel, and nearly 

 every other article in the production of which great heat was required, and having 

 proved in nearly every case successful, it had ceased to be an experimental system, 

 and had become an established and recognized success. The paper then described, 

 by the aid of diagrams, the construction of the furnace in which the gas was burnt, 

 and the gas-producers for all descriptions of fuel. By this process a flame was ob- 

 tained (equal to a white heat) which did not contain anything that could injuri- 

 ously affect the most delicate manufacture, for even sulphuring was prevented, for the 

 sulphur in separating from its hydrogen took up oxygen supplied by the carbonic 

 acid and water, forming sulphurous acid, — a stable compound, which was not de- 

 composed on meeting metallic oxides in the furnace. The nature and intensity of 

 the flame was also under the instant control of the man in charge of the furnace, 

 so that the chemical nature of the flame could be altered at will — one minute an 

 oxidizing flame being obtained, and the next a reducing or carbonizing one. So 

 also the amount of the flame could be altered from the smallest flicker to the com- 

 plete filling of the chamber with an intense body of fiame. The paper pointed out 

 the immense advantage thus obtained in furnaces where the delicate operation of 

 heating or melting steel was carried on ; and for reheating purposes, especially for 

 reheating steel blooms and ingots. The advantage of the system was a large saving 

 of fuel. A ton of steel by the furnace was melted with an average weight of a ton 



1865. 12 



